Colin Kaepernick, the San Francisco 49ers quarterback whose controversial decision not to stand during the National Anthem propelled him into the national spotlight this summer, has sparked debate once again with his choice not to vote in the presidential election.

Mr. Kaepernick, whose on-the-field protests against the killings of black men at the hands of police inspired some and enraged others, attracted a new wave of critics on Tuesday when he revealed to a San Francisco Chronicle reporter that he had not voted and didn't intend to.

His answer came under fire by some who argued that by not voting, Kaepernick was missing an opportunity to back up his protests with political action by participating in the democratic process.

"Kaepernick suggested that he didn’t vote because he didn't see any election result dismantling systemic racism in this country. That may be true," wrote one critic, ESPN panelist Kevin B. Blackistone, in an op-ed for The Washington Post. "But being dismissive of the process for such a reason ran counter to the reason to protest. It signaled defeat. It conceded victory. It recognized as supreme the very paradigm he sought to shift."

But the quarterback stuck by his decision, defending the choice this past weekend, despite the victory of Republican candidate Donald Trump.

"You know, I think it would be hypocritical of me to vote," Mr. Kaepernick told The San Francisco Chronicle on Sunday. "I said from the beginning I was against oppression, I was against the system of oppression. I’m not going to show support for that system. And to me, the oppressor isn’t going to allow you to vote your way out of your oppression."

Kaepernick's election boycott, while debatable in its effectiveness, was not unprecedented. In 2009, Mexican voters disgruntled with their politicians started a popular campaign for "Nulo" – Spanish for null and void – urging voters to nullify their ballots and vote for no one at all. Supporters of the Nulo campaign believed that the lack of votes could send a message to those in charge; opponents of the campaign argued that those boycotted the election were detracting from the democratic process by allowing others to decide the fate of the country.

Several years earlier, in 2005, fewer than 25 percent of Venezuelans participated in the country's congressional elections, with five opposition parties boycotting on the grounds that the nation's electoral authority was biased toward President Hugo Chávez's allies, resulting in a landslide victory for said allies.

"These people don't trust the system," Carlos Albrizzio, director of one of several voting centers in the opposition-dominated Caracas neighborhood of Altamira told The Christian Science Monitor at the time. "They don't want to support it with their vote."

While voter turnout for the US presidential election last week was significantly higher, with about 57 percent of eligible voters casting ballots, voter turnout numbers suggest that Kaepernick was not alone in choosing not to vote: the percent of eligible voters casting ballots in 2016 was down from 58.6 percent in 2012 and 61.6 percent in 2008. (Turnout remained higher, however, than most presidential election years from 1972 to 2000.)

In the weeks leading up to the election, Millennial voters in particular showed waning enthusiasm for voting, with nearly half of those surveyed saying that their vote "doesn't really matter," as David Iaconangelo reported in October.

"Certainly, this is not an election that’s going to teach young people to have a great deal of faith in American political processes," Kay Schlozman, a political scientist at Boston College, told the Monitor at the time. "I worry about that. I know that democracies work better when they trust each other and they trust the government."